KR20020020761A - Tampon having apertured film cover thermobonded to fibrous absorbent structure - Google Patents

Abstract

Tampons having an absorbent structure and a perforated film cover that are heat bonded to the absorbent structure are described. This cover is bonded to the absorbent structure through a number of discrete spots disposed with respect to the surface of the absorbent structure to provide bonding of the overlapped cover with the absorbent. Bonding the overlapped cover with the absorbent has a shear strength of at least about 3N. A plurality of heat-bonded discrete spots form a bonded area and a bonded spot and the non-bonded portions between the spots form a bonded area. Suitably, the bonded area covers about 5% to about 30% of the bonding area. In addition, a sealing member for a sealing roller is described. The sealing member outlines a sealing pattern formed by the sealing knobs protruding from the base of the sealing member and disposed apart from each other. Each sealing knob has a perimeter formed to exclude gradual edges.

Description

Tampon having apertured film cover thermobonded to fibrous absorbent structure

U.S. Patent 4,816,100 describes a method and apparatus for making feminine hygiene tampons. This method provides liquid permeability and at least partially the thermoplastic packaging material is applied to the fleece web by heat sealing and divided into sections. The fleece web section serving as the fleece web is wound on itself to form a tampon blank with a recovery cord. The liquid permeable packaging material is thereby positioned at and substantially surrounds the tampon blank. Finally, the tampon blank is pressed radially into the final shape of the tampon.

While this has always been developed for tampon technology, it has recently been inserted using film covers perforated in tampons. These covers present additional problems, especially when firmly attached by heat sealing. For example, the heat seal can also block the holes of the liquid impermeable plastic film.

Thus, there has been a need for tampons with perforated film covers that are rigidly secured to absorbent structures that do not adversely affect the absorbent properties of tampons.

This application is pending US patent application Ser. No. 09 / 343,759, 09 / 345,090, 09 / 345,089, 09 / 343,760, 09 / 345,088, 60, filed on June 30, 1999. / 141,688, and 60 / 141,690, and the invention also refers to "sealing rollers and sealing roller elements for producing feminine hygiene tampons and methods of making the same" (Attorney Docket J & J-1914) and "female Sanitary tampons and methods for manufacturing the same and apparatuses thereof (Attorney Docket J & J-1924).

FIELD OF THE INVENTION The present invention relates to tampons suitable for feminine hygiene having a perforated film cover heat bonded to an absorbent structure and a method for making the tampons.

1 is a perspective view of a tampon according to the present invention.

2 is a plan view of an absorbent web having a perforated film cover attached through a pattern of heat bonded discrete spots.

3 is a side cross-sectional view of a spirally wound tampon blank with a perforated film cover attached thereto.

4 is a perspective view of a sealing roller useful for making tampons according to the present invention.

4A is a plan view taken along the outer circumference of the sealing member of FIG. 4.

5A-5C are cross-sectional views of various sealing knobs of the sealing member of FIG. 4.

6 is a partial cross-sectional view of the sealing member taken along line 6-6 of FIG.

Tampons having an absorbent structure and a perforated film cover that are heat bonded to the absorbent structure are described. The cover is bonded to the absorbent structure through a plurality of discrete spots arranged about the surface of the absorbent structure to provide bonding of the overlapped cover with the absorbent. Bonding the overlapped cover with the absorbent has a shear strength of at least approximately 3N. The plurality of heat-bonded discrete spots form a bonded area and a bonded spot and the non-bonded portions between the spots form a bonded area. Suitably, the bonded area covers approximately 5% to 30% of the bonding area.

In addition, a sealing member for a sealing roller is described. The sealing member protrudes from the base of the sealing member and creates a sealing pattern formed by the sealing knobs arranged to be spaced apart from each other.

As used herein, the term "perforated film" refers to a fluid impermeable plastic material in the form of an elastic three-dimensional web having first and second surfaces and exhibiting a fibrous appearance and feel. The first surface of the three-dimensional web has a number of holes therein. Suitably, each hole is formed by some intersecting fibrous elements that are substantially interconnected with each other in the plane of the first surface. Each fibrous element exhibits a cross section that preferably has a base portion and sidewalls bonded to each edge of the base portion in the plane of the first surface. The side wall portion extends in the direction of the second surface of the three-dimensional web. Furthermore, the intersecting sidewall portions are interconnected to each other via the first and second surfaces of the web. The interconnected sidewall portions are connected with each other substantially in the plane of the second surface.

As used herein, the term "cover" refers to an element of an absorbent article that substantially surrounds the absorbent structure only with or in association with one or more elements. The term refers substantially to the device disposed on the other surface of the tampon.

A tampon with a perforated film cover is shown in FIG. 1. This chamfer 10 is formed of an absorbent structure having an insertion end 12 and a distal end 14 and substantially covered by a perforated film material or cover 18. In addition, the recovery string 20 extends from the distal end 14 of the tampon 10.

The absorbent structure can be any absorbent means capable of absorbing and / or maintaining liquids (eg menses). Absorbent structures can be made in a wide variety of sizes and shapes and in a wide variety of liquid absorbing materials. A representative list of non-formal useful materials is cellulose such as rayon, cotton, wood pulp, crepe cellulose weddings, tissue wraps and laminates, peat moss, and chemically reinforced, modified or crosslinked cellulose fibers. Materials; Polymeric materials such as polyester fibers, polyolefin fibers, absorbent foams, absorbent sponges, superabsorbent polymers, absorbent gelling materials; Formed fibers such as capillary channel fibers and multi-winged fibers; Combinations of materials such as synthetic fibers and wood pulp with fiber structures formed together (these materials described in US Pat. No. 4,100,324 to Anderson et al.); Or any equivalent material or combination or mixture of these materials. Suitably, the absorbent structure includes one or more devices to provide structural stability. This structural stability allows the absorbent structure to adhere firmly to the cover. Examples of representative non-formal devices that provide structural stability include fiber webs, films, and the like.

The cover of the present invention can be made by standard processes known to those skilled in the art. For example, the base film to be perforated can be extruded, cast, or blown to form a film. The base film may be a single formed polymeric material or mixture, or US patent application Ser. No. 09 / 345,090 to Johnson et al. And US patents such as Gel et al. It may be a laminated or multilayer material as described in application 09 / 345,089. Useful techniques for forming these films are readily appreciated by those skilled in the art. The base film will then be perforated by any useful method. Some examples include hot air drilling and water jet drilling. Examples of these processes are described in Curro, US Pat. No. 4,695,422; Turi, US Pat. No. 5,567,376 and; Described in U.S. Patent 4,471,877 to Mullan, the description of each of these patents is referred to herein. The finally perforated film is assigned to the applicant and is pending US Patent Application No. 09 / entitled "Tampon with cover and nonionic surfactant" (Attorney Docket PPC-708). 345,088 and / or slit to the required width for use in tampon manufacture.

The cover 18 is intended to reduce, suitably, prevent the likelihood that any sufficient portion of the absorbent structure 16 is discharged from the tampon 10 and retained after the tampon 10 has been pulled out of the recovery string 20 and removed. It is useful to include absorbent structural materials. The cover 18 also protects the tissue in contact with the tampon from excessive friction or other irritation during insertion, use and removal of the tampon 10. Furthermore, cover 18 may add aesthetics to tampon 10. Thus, the cover 18 preferably has properties such as low friction coefficient, smooth surface, high opacity, clean pores, and insoluble appearance.

Since the cover 18 includes the absorbent structure 16, the cover 18 and the absorbent structure 16 may be at least self heat bonded to each other by fixing the absorbent structure 16 therein. In addition, the cover 18 may also heat bond itself to the outer portion of the absorbent structure 16.

The perforated film cover 18 is attached to the absorbent structure 16 through a plurality of discrete spots 22 that are heat bonded. These spots 22 are arranged to provide a thermal bond with a relatively small area over a relatively large surface of the tampon 10. The area of the thermally bonded portion forms a bonded spot with the bonded area, and the non-bonded portions between the spots gather to provide for forming the bonded area 24. The bonded area covers about 5% to 30% of the bonding area, suitably about 10% to 20% of the bonding area 24 and most suitably about 15% to 20% of the bonding area 24.

The amount of coverage of the junction region is less than the coverage obtained in the prior art, for example US Pat. No. 4,816,100. Commercial examples of tampons have a sealing pattern of continuous oblique lines covering about 40% of the bonded area.

The plurality of discrete spots 22 that are heat bonded cooperate to provide bonding of the overlapped cover and the absorbent. This bonding maintains the stiffness of the covered tampons in sufficient strength during manufacture, storage and use. The measurement of this bond is made by determining the shear force required to separate the cover from the absorbent structure. The method for determining this strength is described below. The bonding of the overlapped cover and the absorbent is at least about 3N. This shear force provides sufficient strength to assure the user that the cover remains with the absorbent structure during use, in particular during removal. Suitably, the cover to absorbent shear strength is at least about 2N, more suitably the shear strength of the bond is about 3N to about 10N.

One method for applying the perforated film cover material to the absorbent structure in the manufacture of tampons is to use a cut-placement unit to cut the material from the slit roll and place it in the absorbent structure. Another method is described in US Pat. No. 4,816,100, which is incorporated herein by reference. While this describes the application of the nonwoven cover to tampons, the improvement necessary to achieve this is assigned to the applicant and the pending invention is entitled “Continuous Method of Providing Independent Sheets of Continuous Webs”. And US patent application Ser. No. 09 / 343,759, filed June 30, 1999, which is incorporated herein by reference. The pending patent application includes cutting the feed material in a plurality of discrete areas along the transverse axis, recording the remaining material between the cut areas along the same transverse axis, and a force sufficient to break the recorded area. A method for achieving a total separation of a material cross section is disclosed which comprises separating the material cross section from its supply by applying a. The cross section of material subdues the cover of the present invention and, as described in the patent, the cover is heat bonded to the nonwoven absorbent web.

Thermal bonding is suitably achieved through the use of the sealing member 40 of the sealing roller 42 created by the sealing pattern (shown in FIG. 4). According to the present invention, the sealing pattern is formed by protrusions projecting from the sealing knob 44 or the base 46 of the sealing member 40. Suitably, the sealing knob 44 has an outer angle α (shown in FIG. 5) formed between the cover and the sealing surface 50 of the sealing knob 44 which is compressed in contact with the knob sidewall 52. It has a circular edge 48 or an edge 48. Suitably, external angle (alpha) is 180 degree or more and 240 degrees. This sealing member 40 prevents damage to the cover which impairs not only the function of the tampon but also its appearance. Since the acute edge 48 is not applied to the cover 180, the pressure and temperature applied to the cover 18 by the sealing member 40 are the prior art seals without causing injury and damage to the cover material 18. Much higher than absence.

It is suitable to avoid sharp edges or overhangs on the sealing knob. A suitable contour of the sealing knob 44 according to the invention is a soft circle from the sealing face 50 to the knob side wall 52. Sealing surface 50 of knob 44 may have any shape generally desired to provide the shape to a heat sealed spot. For example, the sealing surface 50 may be generally circular, elliptical, polygonal, and curved. Suitably, the sealing surface 50 may be substantially circular, oval or elliptical in order to minimize the risk of damage or injury to the cover material to be sealed. In particular, the sealing surface is substantially oval (or rectangular with substantially hemispherical ends). These contours provide a reliable heat bond between the cover and the absorbent structure even when the system is exposed to moisture.

In a suitable embodiment, the sealing knob 44 is disposed on the sealing member 40 in obliquely spaced rows. The configuration of the sealing knob 44 may change for visual reasons. The dimensions and configuration of the sealing knob can be preferably selected. However, the distance d between adjacent sealing knobs may not be too large or reliable contact between the cover 18 and the absorbent structure 16 cross section may not occur. In addition, it is possible for the knob 44 to have a meaning when forming or combining. The sealing knob 44 is suitably provided in the edge 56 and the edge part 58 area | region at the front end 54 of the sealing member 40 as viewed in the rotation direction x. This position of the knob 44 prevents unnecessary movement of the cover material 18 and makes it possible to firmly attach the cover 18 to the absorbent structure 16.

Suitable oval surface sealing knob 44 has a length of about 5.5 mm and a width of about 3 mm. For rounded ends and contours, this can make a sealing knob with an independent sealing area of about 14.7 mm ² . However, each independent sealing surface preferably has an area of less than about 40 mm ² , more suitably less than about 25 mm ² , and most suitably an area of about 5 to 15 mm ² . This sealing surface provides a corresponding surface area for discrete spots that are heat bonded in the cover / absorbent structure.

Suitably, the adjacent sealing knobs 44 are not separated by a distance d of at least about 2 mm, and more suitably, the adjacent sealing knobs are within about 3 mm to about 15 mm, most suitably within about 5 mm to about 10 mm. . Of course, the placement of the sealing knob 44 determines the corresponding space of the spot 22 heat-bonded on the tampon blank and the final tampon product.

In general, the sealing knob 44 is uniformly distributed with respect to the sealing member 40. However, it is useful to reduce the space between them in the edge region of the sealing member 40 to securely fix the outer circumference of the cover material 18 to the absorbent structure 16.

Suitably, the sealing knob 44 is arranged in a pattern aligned at an oblique angle to the outer circumference of the sealing roller 42. This may be particularly noticeable when the sealing knob 44 has a more rectangular or egg shape. This angle causes the liquid flow along the surface of the tampon to deviate from a straight line along the length of the tampon. This has two effects. First, the distance that liquid flows at the surface of the tampon increases because it deviates from the straight line along the tampon. This improves the likelihood that the liquid will be absorbed. Secondly, the heat bonded discrete spots 22 do not provide a straight line of flow along the tampon. This can provide an improved specific absorption area around the bonded spots to improve the overall absorption performance of the tampons.

There are a number of lines of sealing knobs 44 that are observed across the sealing member 40. In a suitable embodiment, there are about 2 to about 10 lines, suitably about 3 to about 7 lines, most suitably about 3 to about 5 lines of the sealing knob 44 across the face of the sealing member 40. . In this embodiment, the sealing knobs 44 are staggered to be several sealing knobs 44 that bond the cover to the absorbent structure rather than in the line of the sealing knobs 44. This is of prior art The pressure exerted on the cover / absorbent structure is increased with the same force as compared to a continuous line of products. The force used in the prior art products will be applied to smaller areas to provide greater bonding pressure and to improve the overall strength of the bonding of the cover and absorbent.

The heat-bonded discrete spot 22 is suitably joined in such a way that the holes in the cover material are not sufficiently blocked, and the heat-bonded spot 22 draws fluid through the holes in the cover in the heat-bonded spot 22. I can deliver it.

The sealing member 40 is made of a heat conductive material. Non-formal lists of representative materials include steels, including stainless steel, mild steel, tool steel, and the like, and metals such as aluminum. Useful stainless steels include 300 series, including 303, 304, and 306, 400 series, and 800 series. Useful aluminum alloys include the 2000 series, including 2024, the 3000 series, including 3003, the 5000 series, including 5052 and 5080, the 6000 series, including 6061, 6063 and 6082, and the 7000 series, including 7075. do. These materials are coated with a suitable coating to protect the sealing member from corrosion and abrasion and to reduce the likelihood that the sealing material will adhere to the tooling surface. Such materials will be recognized by those skilled in the art.

The heating element is associated with the sealing member 40 in a manner to provide the sealing knob 44 with well controlled heat. Suitably, the heating element can be controlled to provide accurate heat of +/- 5 ° C, more suitably +/- 2 ° C. This can be achieved by placing two heating elements symmetrical in the intermediate position of the sealing member 4 or three or more elements in a suitable position on the sealing member. Alternatively, it can be integrated with conduits within the heating element 40 to use a single plate heating element or to receive a circulating heating fluid. Further, a temperature control element such as a thermocouple can be provided in proximity to the sealing member, for example, in the intermediate plane of the sealing member 40.

In addition to the sealing knob 44, the sealing member suitably includes a thermal insulation material 60 between the unsealed knob 44 and at the portion of the sealing member 40 around it as shown in FIG. 6. This insulating material 60 may be any thermally insulating material that is effective at the operating temperature of the sealing or bonding process. Examples of representative non-formal thermal insulation materials include elastomeric materials such as latex rubber, silicone rubber, elastomeric block copolymers, and the like, and high temperature based on polytetrafluoroethylene (PTFE) known as "PEEK" according to European DIN standards. Plastics and the like. Suitably, the insulating material is a medically approved elastomer or at least restorative, and more suitably, the insulating material can be obtained from Ensinger GmbH & Co. of New Pringen, Germany. High temperature plastic having a glass transition temperature of at least about 140 ° C., such as a fiber reinforcement comprising a TECAPEEK material. The insulating material 60 is in good contact with the base 46 of the sealing member 40 at the distal end 58 and the distal end 62 of the sealing member 40 when viewed along the direction of rotation x. The gap is separated by a small gap g. This gap is generally less than about 1 mm, more suitably more than about 0.2 mm to about 0.7 mm, most suitably about 0.5 mm. This gap allows major movement of the insulating material, considered as the fleece web thickness passing through the nip between the sealing member 40 and the pressure roller 64. The pressure faced by the fleece web in this nip represents the fleece web to maintain a relatively uniform density during processing.

The insulating material 60 typically has a thickness of about 1 to 4 mm, preferably about 2 mm. This insulating material 60 may be of uniform thickness as described above (as well as excluding the holes necessary for the sealing knob 44 to protrude through), and one or more recesses formed therein. Can be. For example, a substantially rectangular recess 61 can be formed in the surface of the insulating material 60 facing the base 46 of the sealing member 40. The recess 61 can increase the flexibility of the insulating material 60 and can act as a spring member to assist in providing a substantially uniform pressure to the cover / absorbent structure. The recess 61 may have a depth of approximately 10-50% of the thickness of the insulating material 60.

The sealing knob 44 typically protrudes from the base 46 of the sealing member 40 and is at least about 1 mm, preferably about 3 to 7 mm, most preferably about 5 mm above the insulating material 60. Is extended by.

The invention also relates to a method of making a feminine hygiene tampon. In particular, the present invention includes heating bonding at least a temperature of a cover material that is at least partially thermoplastic to the absorbent structure.

Typical bonding temperatures are 140 ° C. for fleece webs containing cotton and rayon or rayon mixtures, and perforated film covers containing polyethylene. This provides a reliable heat seal of the material used. The cover material is bonded to the fleece web section at the required bonding area and the rest of the cover material obtains a temperature that does not cause bonding or damage.

4 is a perspective view of the fleece web section 16 with the sealing roller and the cover 18 adhered thereto. The sealing member 40 has sealing knobs 44 arranged laterally spaced apart from each other, and the sealing knobs 44 protrude approximately 0.3 cm from the base 46 of the sealing member 40.

According to FIGS. 4 and 4A, the sealing knob 44 has a sealing surface 50 that is substantially egg-shaped and rounded. The transition from each sealing surface 50 to the knob sidewall 52 is substantially perpendicular to the base 46 of the sealing member 40. Thus, portions of the sealing knob 44 in contact with the fleece web section 16 and / or the cover material 18 do not have a sharp edge.

The pressing roller 64 presses the fleece web 16 against the sealing roller 42, so that the packing material is tightly sealed by the sealing member 40 on the fleece web. In addition, another conveying and / or driving roller 66 is provided that drives the fleece web 16 and holds it in the desired direction.

At the time of operation, the sealing member 40 is usually heated to a temperature of 140 ° C. This usually makes the surface temperature of the sealing surface 52 approximately 140 ° C.

A selection member consisting of the remaining segments of the sealing roller cylinder can be inserted into the sealing roller 42 in the void 68. These members are filed on the same date as the present application, the contents of which are incorporated herein by reference, and are entitled "Sealing Rollers and Sealing Roller Members and Methods for Producing Feminine Hygiene Tampons" Ironing member disclosed in Attorney Docket J & J-1914.

5 schematically shows, in cross-section, various embodiments of the sealing knob 44 of the sealing member 140.

The sealing knob 44 shown in FIG. 5A is substantially rectangular, including a substantially smooth sealing surface 50 and a smooth knob sidewall 52 arranged substantially perpendicular to the sealing surface 50. The edge between the sealing surface 50 and the knob side wall 52 is rounded. The rounding treatment is not provided at the edges between the knob sidewall 52 and the base 46 of the sealing member, which is the fleece web 100, the fleece web section 105 when the sealing roller 42 is in operation. ) Or the packaging material 200.

5B shows another embodiment of a sealing knob 44 that includes a smooth sealing surface 50 and laterally arranged knob sidewalls 52. The external angle between the sealing surface 50 and the knob sidewall 52 is about 225 ° and the angle between the base 46 and the knob sidewall 52 is about 135 °. The obtuse angle of the edges prevents damage to the material to be treated.

5C shows another embodiment of the sealing knob 44 in the shape of an elliptical piece. This oval piece-shaped sealing knob 44 firmly attaches the cover 16 and does not damage the cover material.

Although the present description refers to the sealing roller 42 of FIG. 4, those skilled in the art will appreciate that the sealing member 40 may be made of a substantially planar element or other physical configuration capable of reciprocating motion providing proper temperature and pressure. I will understand that.

Shear strength test method

This test method determines the seal strength between an absorbent structure and an adjacent material, such as a tampon's cover.

1. Test Equipment: Tensile testing machines such as computer controlled Instron Model 1011 (Instron Model 1011; 50N force transducer, 500 mm pneumatic grip); Software such as WININ to operate the tensile tester and display the results; Balance (0.01 g precision); And Eppendorf pipettes or similar pipettes (adjustable volume up to 5 ml).

2. Specimen Preparation: Ten tampons were selected and ones with a target weight of ± 0.1 g were selected. The selected tampon is soaked and loosened with approximately 4 ml of water (Eppendorf pipette) to arrange the absorbent structure and cover in a substantially planar configuration as needed, and the length of the sealing area is measured and recorded. In addition, if desired, the absorbent structure is cut to leave only a small amount (at least 2 cm) of structure extending beyond the seal of the cover material to provide a gripping portion for the test equipment. The absorbent structure and the cover end are fastened in the tester.

3. Computer controlled Instron instrument configuration:

-Testing speed: 100mm / min

Test Method: Tensile Test

Breakage behavior: in case of breakage stops the test and returns the grip to the starting position

Load range: 20%

Breakage detector sensitivity: 20%

Peak detector sensitivity: 5%

4. Start the test for each specimen:

-By adjusting the distance between the grips of the tester to fix the product to be tested, placing the cover material in the upper grip when fitted

-Mechanically adjustable lower limit stops properly under the lower grip;

-Adjust the display of force as needed

-Coupling test, measurement can be stopped using the "STOP" button after the force has peaked

-Record the highest force as the seal strength

-Repeat for each specimen

The foregoing is disclosed to aid a non-limiting complete understanding of the invention disclosed herein. Since various modifications and embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the following claims.

Claims (23)

Absorbent structure, A perforated film cover heat bonded to the absorbent structure through a plurality of discrete spots arranged around the surface of the absorbent structure to provide bonding of the overlapped cover and the absorbent material, Tampon bonding of the overlapped cover to the absorbent has a shear strength of at least about 2N. The tampon of claim 1, wherein the absorbent structure comprises a fibrous web. The tampon of claim 2, wherein the fibrous web comprises synthetic fibers, natural fibers, or a combination thereof. 2. The perforated film cover of claim 1, wherein the perforated film cover comprises a fluid impermeable plastic material in the form of an elastic three-dimensional web exhibiting a fibrous appearance and feel, wherein the web has a first and a second surface, and the first The surface is at least partially formed by one of the first and second layers and has a plurality of holes therein, each of the holes having a plurality of intersecting fibrous elements substantially interconnected in the plane of the first surface. And each of the fibrous elements exhibits a cross section comprising a base portion and sidewall portions joined to respective edges of the base portion in the plane of the first surface, the sidewall portions generally extending in a direction toward a second surface of the web. Wherein the intersecting sidewall portions are interconnected via first and second surfaces of the web, and wherein the interconnected sidewall portions of the second surface Tampons terminated substantially simultaneously with one another in the plane. The tampon of claim 1, wherein the perforated film comprises a polymeric material selected from the group consisting of polyolefins, polyesters, polyamides, polyurethanes, polystyrenes, halogenated polymers, and copolymers thereof. The method of claim 1, wherein the plurality of discretely heated spots form a bonded spot and a bonded spot, the non-bonded portions between the spots forming a bonded area, wherein the bonded area is approximately 5 of the bonded area. Tampons covering% to approximately 30%. The tampon of claim 6, wherein the bonded area covers about 10% to about 25% of the bond area. 8. The tampon of claim 7, wherein the bonded area covers approximately 15% to approximately 20% of the bonded area. As a sealing member for a sealing roller, The sealing member has a contour of a sealing pattern, and the sealing pattern is formed by sealing knobs protruding from the base of the sealing member and disposed apart from each other, wherein each sealing knob has an outer circumference formed to exclude an aggregate edge. . 10. The sealing member according to claim 9, wherein an outer circumference of the sealing member is rounded. 10. The sealing member according to claim 9, wherein an outer circumference of the sealing member is formed at an angle greater than about 180 degrees to 240 degrees. 10. The sealing member according to claim 9, wherein the sealing knob has a substantially spherical shape. 10. The sealing member according to claim 9, wherein the sealing knob has a substantially spherical segment shape. 10. The sealing member of claim 9, wherein the sealing knob is formed of substantially elliptical segments. 10. The sealing member according to claim 9, wherein the sealing knob is located in rows arranged laterally apart from each other on the sealing member. 10. The sealing member according to claim 9, wherein the sealing knob protrudes at least 3 mm from the base of the sealing member. 10. The sealing member according to claim 9, further comprising an insulating material adjacent said sealing knob. 18. The sealing member according to claim 17, wherein said sealing knob protrudes at least 1 mm from an insulating material. 10. The sealing member according to claim 9, wherein a sealing knob is provided at least at an edge and a corner of the front end in the rotational direction of the sealing member. The sealing member of claim 9, wherein the sealing knob covers approximately 5% to 30% of the planar surface area of the sealing member. Heat bonding the perforated film cover to the absorbent structure through a plurality of discrete spots arranged around the surface of the absorbent structure to provide bonding of the absorbent with the overlapped cover having a shear force of at least about 2 N; Forming a tampon with the absorbent structure and the perforated film cover. The tampon of claim 1, wherein the sealing knob has a sealing area of less than about 40 mm ² . The sealing member of claim 9, wherein the sealing knob has a sealing area of less than about 40 mm ² .